Eco-friendly hydroxyapatite and emerging MXenes for uranium adsorptive uptake

Abstract

Uranium is a nuclear contaminant possessing radioactivity and chemical toxicity. It can be discharged into the environment from multiple sources such as uranium ore mining and hydrometallurgy, used nuclear fuel disposal and nuclear accidents. Uranium could be a growing threat to human survival and biodiversity if it is released into the environment without treatment. As one of the treatment technologies, uranium adsorption, therefore, has become an important research area. The traditional eco-friendly hydroxyapatite (HAP) and emerging MXenes have been proved to serve as potentially ideal adsorbents for uranium while there is no review about their uranium adsorption. In this paper, the recent research status of HAP and MXenes as uranium adsorbents is overviewed. The uranium adsorption capacity, adsorption influencing factors, and interaction mechanisms of these two types of materials are discussed. In addition, MXenes are a new class of two-dimensional materials, and their synthesis methods are constantly updated. Thus, the latest progress of the preparation methods of MXenes is reviewed in detail. Furthermore, we have pointed out some challenges in their use for uranium adsorption and suggested possible future research directions.